The present invention is directed to thin-walled containers, particularly those composed of a strain hardened polymer, having a portion of the side wall of the container formed to permit the container to be gripped between a thumb and fingers of one hand.
Thin-walled thermoplastic polymeric containers have been adapted for use to contain a wide range of products. The advantageous features of such thin walled polymeric containers are well known and include the low cost of production, and light weight which contributes to reducing the transportation costs for the goods contained within such containers. Some containers have been designed to include a pair of opposed, inwardly projecting, indentations on opposite sides of the container which indentations are so situated as to permit the container as a whole to be easily grasped between the thumb and fingers of one hand. While such indentations enhance the handling characteristics of the bottle relative to pouring liquid product from the bottle, the hand-grip indentations have presented some problems.
When containers having hand-grip indentations of the type generally discussed above are to be filled with liquid, the position of the fill line within the container is generally designed taking into account the volume occupied by the hand-grip indentations themselves. In the event that the hand-grip indentations evert to an outwardly projecting rather than an inwardly projecting position, the total volume of the container generally increases thereby lowering the level of product within the container. Where consumers are accustomed to seeing product within a container at a given level, the presence of everted indentation presents the disturbing appearance of there being less than the normal amount of product within the container which, in turn, detrimentally affects the customer's willingness to buy the product within the container.
The everting of the hand-grips has been observed to occur quite easily, particularly in the 1.75 liter size commonly used in the liquor industry. It has been observed that the hydraulic shock caused by the dropping of a full container less than two feet can cause conventional hand-grip indentations to evert. Where the containers are warm due to the environmental conditions imposed by shipment during hot weather, the everted hand-grip indentations may take a set in the outwardly projecting position to such a point that the hand-grips of the container will not retain the initially designed, inwardly projecting configuration.